Coupling for composite hose and method of making same

ABSTRACT

A reinforced hose coupling including an end fitting having first and second, axially extending sections with the first section comprising a connector and a second section providing a nipple with external grooves. A metal ferrule is mounted on the nipple and is connected to the end fitting. The ferrule has an external depression formed in a side thereof. Two holes are formed in this depression and extend through the wall of the ferrule. A reinforced hose end having flexible tubular rubber or plastic layers is crimped between the ferrule and the nipple. The hose end has an outer wire extending about the exterior of the tubular layers. An end piece of this wire extends through the holes and across the depression helping to secure the hose end to the coupling and providing an indication to the user that the coupling is in usable condition. Preferably the ferrule is formed with a circumferentially extending internal rim at one end, which rim is forced into a circumferential groove formed in the end-fitting. A method and an apparatus are also provided for making the house coupling. The apparatus includes first and second annular dies each having a circular die opening with a predetermined minimum diameter. A mounting arrangement rigidly connects each die to a hydraulic ram so that each can be driven linearly along the exterior of the ferrule.

BACKGROUND OF THE INVENTION

[0001] This invention relates to flexible hose couplings, particularlycouplings suitable for use with reinforced hose, a method of making suchcouplings, and die apparatus for making the couplings.

[0002] A variety of hose couplings for flexible rubber and plastic hosesare known including couplings suitable for textile reinforced and metalreinforced hose. In many cases these couplings comprise two mainmembers, one of which is a nipple or end fitting having a portionthereof that is inserted into the end of the hose, and the other ofwhich is a metal ferrule or sleeve member that extends about theexterior of the hose end. Often the ferrule is mechanically connected tothe nipple member such as by means of threads or by an internal rimformed on one end of the ferrule, which end is driven into acircumferential groove formed in the nipple member. The ferrule or outersleeve is made crimpable. By using a die set, the ferrule can be crimpedor forced inwardly to clamp the hose end tightly between the ferrule andthe nipple member.

[0003] U.S. Pat. No. 3,835,891 which issued Sep. 17, 1974 to CompoflexCompany Limited is illustrative of a high pressure flexible hosedeveloped in recent years and employing inner and outer helical wiresfor reinforcement. This hose may comprise several tubular layers of aplastics material which extends between the helical wires. Theseflexible layers can, for example, comprise fluorinated ethylenepropylene copolymer. The inner helical wire is preferably coated withfluorinated ethylene propylene copolymer of Teflon*. For the conveyanceof chemicals, layers of polypropylene fabric and polypropylene film arelaid on the copolymer. The hose can be covered on its exterior with acoating of PVC (polyvinylchloride). By the use of helical wires on theinside and outside, this type of hose is capable not only ofwithstanding high internal pressures but it is also capable of fullsuction. * Trade-Mark

[0004] A metal coupling for the aforementioned wire reinforced hose isknown in the industry, this coupling comprising a nipple member and asurrounding ferrule or sleeve. An external two start thread is formed ona section of the nipple having a reduced diameter. One of the grooves ofthis thread receives the inner helical wire of the hose while the othergroove accommodates the inward bends of the flexible, tubular portion ofthe hose. The nipple is inserted into the end of the hose by a threadingoperation. An iron of steel ferrule is placed around the hose end and aflexible seal can be arranged adjacent the hose end between the nippleand the ferrule. The ferrule is provided with an inwardly extendingflange or rim at one end. In addition to or instead of theaforementioned seal member, epoxy or other sealant material can beinserted between the ferrule and the end of the hose in order to providea seal in the completed hose coupling. Once the sealing material is inplace, the ferrule is then reduced in diameter by a suitable swagingprocess so that the end of the hose is compressed between the inside ofthe ferrule and the nipple. The swaging process results in a mechanicalconnection which helps to prevent the coupling from coming off the endof the hose. This connection is created between the inner helical wireand the threads or grooves formed on the exterior of the nipple.

[0005] Difficulties have been encountered in the art with theaforementioned coupling designed for a wire reinforced hose. Onedifficulty with this coupling and its method of manufacture arises fromthe tendency of the ferrule to bulge out during the manufacturingprocess. A bulging of the ferrule can result in seal failure. Anotherknown difficulty is that the epoxy or secondary seal used in thecoupling can sometimes be forced out of the space between the ferruleand the hose, leaving gaps or weaknesses in the seal.

[0006] U.S. Pat. No. 3,413,020 issued Nov. 26, 1968 to Samuel Moore &Company describes a fitting designed for composite tubing suitable forhigh pressure applications. The hose can be a polymeric composite tubingthat has an inner helical wire extending about the interior of thetubing and laid along a helical cavity. For purposes of manufacturingthe fitting, the last few turns of the helical wire are removed by meansof pliers and wire cutters. The nipple or inner sleeve is formed with ahelical, external thread which is threaded into the helical cavityformed in the hose end. The hose fitting is completed by an outer sleeveor ferrule having a series of internal teeth. These teeth engage againstthe outside of the hose end by crimping the outer sleeve inwardly. Theferrule is also held in place on the inner sleeve or nipple by means ofthreads formed at one end of the ferrule.

[0007] It is an object of the invention to provide a reinforced hosecoupling which provides a secure connection between a hose end and thefitting itself and which is relatively inexpensive to manufacture.According to one aspect of the invention, the reinforced hose couplingis constructed for use with a reinforced hose end having an exteriorhelical wire. By projecting the end of the helical wire through holesformed in a depression in the side of the ferrule, not only a furthermechanical connection between the hose end and the fitting is provided,but also an indicator that the hose coupling is in good condition foruse.

[0008] It is a further object of the invention to provide a reinforcedhose coupling wherein no separate sealant such as epoxy is required toseal the joint between the hose end and the fitting. The flexibletubular layers of the hose end extend beyond any helical wire thatreinforces the hose and by clamping the extended tubular layers betweenthe ferrule and the nipple member, a fluid tight seal can be formed.

[0009] It is an additional object of the invention to provide a methodfor making a coupling for reinforced flexible hose that has a helicalwire extending about its interior. This manufacturing method can becarried out quickly using a first die and at least one follower die ofsmaller diameter on the metal ferrule of the coupling. It is thefollower die or dies which cause the extension of the tubular layers tobe clamped tightly between the ferrule and the nipple member.

SUMMARY OF THE INVENTION

[0010] According to one aspect of the invention, a reinforced hosecoupling comprises an end fitting having first and second, axiallyextending sections, the first section comprising a connecting elementand the second section providing a nipple element having externalgrooves formed thereon. A metal ferrule is mounted on and about thenipple element and is connected to the endfitting. This ferrule has agenerally cylindrical wall and an external depression formed in a sideof this wall and projecting radially inwardly towards the nippleelement. Two holes are formed in the depression and through the wall. Areinforced hose end having flexible tubular layers is crimped betweenthe ferrule and the nipple element. This hose end has a helical wireextending about the exterior of the flexible tubular layers. An endpiece of this wire extends through one of the holes, across thedepression and back through the other hole.

[0011] Preferably the depression is elongate in the circumferentialdirection of the ferrule and the two holes are formed in opposite endsof the depression.

[0012] According to another aspect of the invention, a reinforced hosecoupling comprises an end fitting having first and second axiallyextending tubular sections, the first and second sections beingseparated by a circumferential groove formed in an exterior surface ofthe end fitting. The first tubular section comprises a connectingelement and the second section has an external helical groove thatspirals about its circumference. There is also provided a flexible hoseend comprising flexible tubular layers of plastics or rubber materialand an inner helical wire extending about the interior of the tubularlayers. The second section of the end fitting extends into the hose endso that the helical wire extends along and in the helical groove andcircumferentially about the second section. An axial extension of thetubular layers extends beyond an adjacent end of the helical wire andalong the exterior of the second section. The coupling includes a metalferrule mounted on the hose end and extending around an end section ofthe helical wire and the axial extension of the tubular layers. Thisferrule has an internal rim at one end which extends into thecircumferential groove in order to mechanically connect the ferrule tothe end fitting. The axial extension of the tubular layers is clampedbetween the ferrule and the end fitting, thereby forming a fluid tightseal.

[0013] In a preferred embodiment of this coupling, the hose end also hasan outer helical wire extending about the exterior of the tubular layersand ending near the adjacent end of the inner helical wire.

[0014] According to a further aspect of the invention, there is provideda method of making a coupling for reinforced flexible hose, which methodincludes providing a flexible hose reinforced by means of a helical wireextending about the interior of the hose and having an end on which acoupling is to be provided. This hose includes flexible tubular layerswhich axially extend beyond an end of the helical wire at the end of thehose. A metal ferrule is placed over the hose and adjacent to the oneend of the hose, this ferrule being formed with a circumferentiallyextending internal rim at an end of the ferrule closest to the one endof the hose. An end fitting is inserted into the one end of the hose,this fitting having first and second axially extending sections, thefirst section comprising a connecting element that projects from the oneend of the hose and the second section providing a nipple element withexternal grooves formed thereon. The nipple element is placed in thehose so that the helical wire extends along the external grooves. Theend fitting has an external, circumferential groove formed therein andspaced from the ends thereof. The metal ferrule is swaged with a firstdie so as to drive the internal rim into the circumferential groove andmechanically connect the ferrule to the end fitting. This step alsoclamps a portion of the helical wire in the external grooves of thenipple element which secures the hose to the end fitting. The metalferrule is then swaged with a follower die of smaller diameter than thefirst die. This step clamps the tubular layers which extend beyond theend of the helical wire tightly between the ferrule and the end fittingin a sealing manner.

[0015] In a preferred version of this method, the end fitting isinserted into the one end of the hose by screwing the fitting relativeto the hose end in order to thread the helical wire into the externalgrooves.

[0016] According to still another aspect of the invention, there isprovided an apparatus for making a coupling for flexible hose reinforcedby means of a helical wire extending about the interior of the hose, theapparatus includes a supporting device for holding one end of the hoseand a generally cylindrical metal ferrule arranged over an end sectionof the hose during operation of the apparatus. The ferrule is formedwith a circumferentially extending internal rim located at an end of theferrule closest to said one end of the hose and having an initial firstexternal diameter. A first annular die forms a circular die openinghaving a minimum diameter a little smaller than said first externaldiameter. A second annular die has a minimum diameter a little smallerthan said minimum diameter of the first die. A mounting arrangement isalso provided for rigidly connecting each of the first and second diesto a hydraulic ram so that each die can be driven linearly along theexterior of the ferrule starting at the end of the ferrule having theinternal rim. The swaging action of the first die causes the end sectionof the hose, including an end portion of the helical wire, to be clampedfirmly between the ferrule and an end fitting positioned within the endsection of the hose, and causes the internal rim to be deformed radiallyinwardly into an annular groove formed around the end-fitting. Asubsequent swaging action with the second die causes a relatively shortend portion of the hose having no helical wire extending about itscircumference to be sealingly clamped between the ferrule and theend-fitting, this further swaging action occurring only along a sectionof the ferrule immediately adjacent said short end portion of the hose.

[0017] According to yet another aspect of the invention, a die apparatusfor swaging a tubular metal body comprises a split die ring forming acircular opening and made up of two semi-annular die sections eachhaving a radially inner surface for engaging and shaping the metal bodyand a radially outer surface which in radial cross-section extends at anacute angle to a central axis of the circular opening. An annular diebody surrounds and supports the die ring, this die body having anannular, sloping engagement surface in contact with the radially outersurface of the die ring and parallel thereto. The die body has a numberof pin passageways that extend radially through the die body. A numberof holding pins each extend through a respective one of the pinpassageways and have a head on a radially outer end thereof. A rotatablecam ring extends about the die body and has a number of slots formedtherein and spaced about the circumference of the cam ring. Each of saidslots extends in a generally circumferential direction and has arespective one of the pin heads captured therein. The pins can be movedradially outwardly by rotation of the cam ring from a first positionwhere inner ends of the pins engage and hold the split die ring in thedie body to a second position where the pins are disengaged from thesplit die ring.

[0018] Further features and advantages will become apparent from thefollowing detailed description taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019]FIG. 1 is a perspective view of a reinforced hose couplingconstructed in accordance with the invention, this coupling including areinforced hose end;

[0020]FIG. 2 is a side view of the combined end fitting or nipplemember, the ferrule, and the hose end section with the lower half of theend fitting, the ferrule and the hose end section being in axialcross-section;

[0021]FIG. 3 is a side view of the reinforced hose coupling afterswaging has been completed, with the ferrule and the hose end sectionbeing shown in axial cross-section for purposes of illustration;

[0022]FIG. 4 is a perspective view of the reinforced hose coupling, witha portion of the coupling cut-away for purposes of illustration;

[0023]FIG. 5 is a detail view comprising a cross-section of thedepression formed in the side of the ferrule of the coupling;

[0024]FIG. 6 is a transverse cross-section of the coupling taken throughthe center of the depression in the ferrule;

[0025]FIG. 7 is a cross-sectional elevation showing the swagingapparatus used to make the hose coupling of the invention; and

[0026]FIG. 8 is a plan view of a die apparatus used in the apparatus ofFIG. 7.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0027] A reinforced hose coupling 10 constructed in accordance with theinvention generally comprises two main components, these being an endfitting or nipple member 12 and a metal ferrule or outer sleeve 14. Inaddition, the hose coupling can include the reinforced hose end 16. Theconstruction of the hose end, which would normally be a portion of along, flexible hose, may vary in its construction depending upon theparticular application to which the hose is to be put. The hose end 16illustrated in FIG. 1 includes several flexible tubular layers 18. Thehose end is shown as cut off at end 20. The illustrated hose endincludes an outer helical wire 22 which extends about the exterior ofthe flexible tubular layers 18. The hose end 16 includes an innerhelical wire 24 extending about the interior of the tubular layers 18.

[0028] In a preferred form of hose sold by Feher Machine & ManufacturingInc. of Sarnia, Ontario, the layers 18 comprise layers of polypropylenefabric and film which give the hose strength and chemical resistancewhile avoiding leakage or weeping. In one preferred form of the hose,the inner layer is a polypropylene reinforcing layer having a thicknessof 2.5- 3 mm. The outer support wire 22 can be made of various types ofwire including galvanized wire, stainless steel wire (type 316),polypropylene coated wire and aluminum wire. The inner wire 24 can begalvanized carbon steel, stainless steel or polypropylene coated wire.

[0029] The hose coupling of the invention can also be used inassociation with other known reinforced flexible hose such as thatdescribed in U.S. Pat. No. 3,835,891. This hose also has inner and outerhelical wires. The hose has an inner lining which includes the innerwire with at least one layer of fluorinated ethylene propylene copolymersuperposed thereon. Layers of polypropylene fabric and polypropylenefilm are laid on the copolymer. There is an outer layer or cover made ofPVC (polyvinylchloride), with this outer cover being surrounded by theouter helical wire.

[0030] A preferred form of end fitting 12 for use in the coupling of theinvention is illustrated in FIGS. 2 and 3. This end fitting can be madeof a variety of materials depending upon the particular application.Suitable materials for this fitting include carbon steel, stainlesssteel (316), aluminum, polypropylene, polyvinylchloride and Teflon*. Theillustrated fitting 12 is made of metal and has first and second,axially extending sections 26 and 28. The first section comprises aconnecting element and may be formed with exterior threads 30 to enablethe fitting to be detachably connected to another fitting (not shown).The second section 28 provides a nipple element sized to fit inside thehose end snugly. This element is preferably provided with externalgrooves 32, the purpose of which is explained hereinafter. Preferablythe grooves 32 form a two start thread which in effect results in therebeing two separate grooves located one beside the other.

[0031] The end fitting 12 is formed with an external, circumferentialgroove 36 which can be machined into the fitting. It is preferablyformed at one end of a short slope 38 formed in the end fitting. Thegroove 36 should not be too deep so as not to weaken the coupling toomuch in this region. *trademark

[0032] The coupling must be designed to withstand anticipated fluidpressures in the hose. With the groove 36 in this preferred position,the groove in effect separates the first and second sections of the endfitting.

[0033] Located between the groove 36 and the grooves 32 is a cylindricalsection 40 of generally uniform diameter. Thus the helical grooves 32extend only from one end 42 of the second section or nipple section 28to a central portion of this second section. Preferably the section 40has one or more small annular grooves 41, 43 formed therein to assist inthe hose end sealing process as explained further below.

[0034] The construction of the ferrule 14 will now be described withreference primarily to FIGS. 2 and 3. The metal ferrule is mounted on orabout the second section or nipple element 28 as shown and it isconnected mechanically to the end fitting 12. The ferrule has agenerally cylindrical wall 44 and, in one preferred version of theinvention shown in FIG. 4, has an external depression 46 formed in aside of this wall for a purpose to be described. The depression projectsradially inwardly towards the second section 28 and two holes 48 and 50are formed in opposite ends of the depression, these holes extendingthrough the wall 44. The depression 46 is preferably elongate in thecircumferential direction of the ferrule.

[0035] In order to enable the ferrule 14 to be mechanically connected tothe end fitting 12, the ferrule is formed with a circumferentiallyextending internal rim 52. As illustrated, this rim extends radiallyinwardly in a direction substantially perpendicular to the cylindricalsurface of the ferrule. The rim 52 is forced by a die into theaforementioned groove 36 as shown in FIG. 3. At the other end of theferrule, a short flare 54 can be formed in order to make it easier toplace the ferrule on the reinforced hose. After the swaging steps arecompleted (as explained in detail below), the ferrule has preferably afirst axially extending portion 56 with a first external diameter and asecond axially extending portion 58 with a second external diameterwhich is somewhat less than the first external diameter. A short slope57 forms a transition region between the portions 56 and 58.

[0036] In order to construct the coupling shown in FIGS. 3 and 4, it isfirst necessary to remove an end section of each of the helical wires 22and 24. If the reinforced hose has only one helical wire, this singlewire would be cut back, the distance depending upon the size of the hoseand the size of the coupling. In the case of a flexible hose having bothinner and outer wires, both wires would be cut back about the samedistance as shown in Figured 2 to 4. The cutting back of the wiresleaves an end portion of the flexible tubular layers 18 which extendsaxially beyond the ends of the helical wires.

[0037] In one embodiment of the present hose coupling, the hose has theaforementioned inner layer of polypropylene reinforcement having athickness of 2.5-3 mm. This reinforcement layer is also cut back fromthe hose end by about {fraction (1/2)} inch or 13 mm. This helps toprevent leaking after completion of the hose coupling by improving thesealing effect between the ferrule and the nipple. The reinforcementlayer is cut back to approximately the first annular groove 41.

[0038] The next step in the assembly process is to place the metalferrule 14 over the hose. In the case where the ferrule is formed withthe depression 46 and the hose has an external helical wire 22, an endpiece 62 of the outer wire is inserted through the first hole 48 andthen through a second hole 50 so that the end piece of the wire extendsacross the length of the depression (making it readily visible from theoutside of the ferrule). After this step, the end fitting 12 is insertedinto the end of the hose by screwing the end fitting relative to the endof the hose in order to thread inner helical wire 24 into one of the twoexternal grooves 32. As shown in FIGS. 2 and 4, the other groove 32accommodates inward bends 66 formed by the tubular layers 18.

[0039] The assembly is then put through a three stage swaging process inorder to complete the hose coupling. The ferrule 14 is swaged with afirst die which forces the internal rim 52 into the groove 36,mechanically connecting the ferrule to the end fitting 12. The ferrule14 is supported at the hose end 70 and it is swaged from the oppositenipple end. This allows the diameter of the ferrule to be smaller at thenipple end as illustrated. The first or leading die is of a diameter sothat it also secures the hose between the ferrule and the second section28. After the first swaging step, the inner wire 24 is held in itsgroove 32. At the same time, the outer wire 22 is held by the wire lockcreated by the end of this wire extending through the depression 46. Theferrule is then swaged with at least one and preferably two followerdies of smaller diameters than the first die, this step or these stepscausing the section 60 of the tubular layers 18 to be tightly clampedbetween the ferrule and the end fitting in a sealing manner. This methodof manufacturing a hose coupling provides a positive leak-proof assemblyand there is no need for a molded seal or the use of special injectedsealant material between the ferrule and the end fitting. Most couplingsconstructed in accordance with the invention can be made to form a sealthat is able to withstand high fluid pressures, as much as 300 psi andmore.

[0040]FIGS. 7 and 8 of the drawings illustrate a preferred apparatus 76for making the hose coupling of the invention. The apparatus includes asupporting device 78 for holding one end of a flexible, reinforced hose80, and the generally cylindrical metal ferrule 14 arranged over an endsection of the hose. The rim 52 of the ferrule is located at the top ofthe upright ferrule and is located at the end of the ferrule closest tothe end 82 of the hose. The supporting device 78 comprises a very rigid,horizontal support plate or table 84 having a central opening 86.Removably mounted in the top of the table 84 is an annular supportmember in the form of a rigid metal locating ring 88 which sits onannular shoulder 90 of the table. The ring 88 forms a circularpassageway 92 through which the hose end can be inserted from below. Thereinforced hose end should fit snugly in the passageway 92 in order tobe supported thereby. Extending about the top of the ring 88 is anannular groove 94 sized to accommodate and locate the bottom end of theferrule 14 before swaging occurs. Suitable means, such as a standardclamp (not shown), can be provided below the table 84 to hold the hoseend in the required position for swaging.

[0041] Arranged above the table 84 a suitable distance is a standard,vertically extending hydraulic ram 96 used for the swaging operation.The bottom end of the ram can be fitted with a rigid, steel supportplate 98 having suitable bolt openings formed therein (not shown) forattaching purposes. As the hydraulic ram and the equipment for operatingsame are of standard construction and correspond to other knownapparatus for swaging operations, a detailed description of thehydraulic ram in the present application is deemed unnecessary.

[0042] As indicated above, in order to carry out the swaging process ofthe invention, at least two dies and preferably three dies are employed.The first or leading die 100 is shown in FIGS. 7 and 8 and it is anannular die forming a circular die opening 102 having a minimum diametera little smaller than the initial first external diameter D of theferrule 14. Set out in Table 1 below are some sample comparativediameters for the first die. A second annular die (not shown) is alsoused and its construction is identical to that of the first die 100except that it has a minimum diameter a little smaller than the minimumdiameter of the first die 100 (see Table 1 below). It will be understoodthat the minimum diameter of this second die would correspond to theexternal diameter of the ferrule portion 58 as shown in FIG. 3.

[0043] The following Table 1 sets out some representive diameterreductions in inches in the ferrule 14 provided by first, second andthird dies that can be used to swage a ferrule of the diameter indicatedin the left hand column: TABLE 1 Ferrule Size 1st Die 2nd Die 3rd Die 1″.114 .112 .060 1 ½″ .164 .122 .066 2″ .153 .121 .065 3″ .220 .117 .063

[0044] A mounting arrangement is provided for rigidly connecting each ofthe first, second, and third dies to the hydraulic ram 96 so that eachdie can be driven linearly along the exterior of the ferrule 14 startingat the end of the ferrule having the rim 52. The preferred mountingarrangement includes an annular mounting ring or die body 103 in whichthe first, the second or the third annular die can be detachably mountedand a rotatable cam ring 104 extending about this mounting ring andmounted thereon. The mounting ring 103 can be formed with an externalshoulder 106 that extends about the circumference of the ring. A short,inwardly projecting flange 108 formed on the cam ring slidably rests onthis shoulder. The mounting ring 103 is itself mounted on a tubularextension 110 that can be detachably connected at its upper end to thesupport plate 98 of the ram. For example, bolts 112 can be used toconnect an upper, outwardly projecting flange 114 to the support 98. Theflange 114 can either be welded to the tubular extension or integrallyformed thereon. A bottom flange 116 can be provided at the bottom end ofthe extension 110 and further bolts 118 can be used to detachablyconnect this flange to the mounting ring. It will be understood that thetubular extension 110 forms a chamber 120 that is sized to accommodatethe end fitting together with ferrule 14 during the swaging actions.

[0045] As shown in FIG. 8, each of the first, second and third annulardies preferably comprises a split die ring made up of two semi-circulardie sections 122, 124. By using a split die ring and the mountingarrangement described herein, it is possible for the operator to releaseeach die even though substantial pressures or forces act on the dieafter the swaging step has been completed. At the same time, each diehas sufficient strength and rigidity to carry out the swaging processproperly while being sufficiently supported by the mounting ring. Theillustrated die sections shown in FIG. 7 have a flat top surface 126, aflat bottom surface 128, an inwardly and downwardly tapering interiorsurface 130 and a rounded, internal corner 132.

[0046] A significant feature of the annular dies and the mounting ring103 on which they are mounted is the manner in which these pieces engageone another. As illustrated in FIG. 7, the annular die 100 has anannular outer surface 134 engaging an annular inner surface 136 of themounting ring 103. In the preferred embodiment, both the outer surface134 and the inner surface 136 extend at an acute angle ranging between10 and 20 degrees to a central axis A of the respective annular die asseen in cross-section through this central axis.

[0047] In the particularly preferred embodiment, the two surfaces 134and 136 extend at an acute angle of about 15 degrees to the central axisA. This angle of engagement is important as it must be sufficientlylarge to permit the split die ring sections to readily disengage fromthe ring 103 when required. The angle must also be small enough that thesplit die ring will be sufficiently supported by the ring 103 so thatthe top and bottom surfaces of the die ring 100 will remainperpendicular to the central axis of the end fitting during the swagingprocess. It should also be noted that the top surface 126 of the diering engages a downwardly facing shoulder 138 of the ring 103, thisshoulder also helping to keep the split die ring in the correctposition.

[0048] The mounting arrangement includes a number of retaining pins 140having heads 142 at their outer ends. The heads 142 are arranged in theaforementioned cam ring 104. The shank of each pin extends through arespective circular passageway 144 formed in the mounting ring 103. In afirst position of the retaining pins, inner ends 146 of the pins engageand hold the split die ring in the mounting ring 103. In this position,the pin ends project into an annular groove 148 formed about theexterior of the split die. It will be seen that the pins 140 can bemoved from the first position shown in FIGS. 7 and 8 where they hold thesplit die ring in the mounting ring 103 to a second position (not shown)where the pins are disengaged from the split die ring 100. This movementof the pins arises from the fact that the cam ring 104 has a number ofslots 150 formed therein and spaced about the circumference of the camring. In the embodiment shown in FIG. 8, there are six of these slots.Each slot extends in a generally circumferential direction and is formedso that the head of its respective pin is captured in the slot. Theshank of the pin extends through a narrow gap or slot 152 that extendsbetween the main slot 150 and the inner surface of the cam ring. Becausethe vertical height of the gap 152 is only slightly more than thediameter of the pin shank, the pin head is secured in its slot 150. Itis also noted that one end 154 of each slot 150 is disposed closer tothe split die than an opposite end 156. Because of this arrangement,rotation of the cam ring 104 in the direction indicated by the arrow Xwill cause each retaining pin 140 to be moved radially outwardly, thusbecoming disengaged from the split die ring. Rotational movement of thecam ring 104 can be done manually or with the use of a suitable toolusing a couple of handles 158 that can be fixedly attached to the camring as indicated in FIG. 8.

[0049] With the hose coupling components in the position shown in FIG. 7and the first split die ring 100 mounted in the ring 103, the ram 96 andthe attached tubular extension 110 are lowered to carry out the firstswaging operation. Downward movement of the die along the ferrule 14causes the end section of the hose, including an end portion of thehelical wire, to be clamped firmly between the ferrule 14 and the endfitting. At the same time, the internal rim 52 is deformed radiallyinwardly into the annular groove 36. Once this initial swaging step iscompleted, the ram 96 is raised to a height sufficient to disengage thesplit ring die 100 from the ferrule. The split ring die is then removedfrom the ring 103 by rotation of the cam ring. The second split ring dieis then inserted into the mounting ring 103 and engaged by means of thepins 140. The ram and the tubular extension are then lowered again for asecond swaging step resulting in the second die being driven along theferrule and, in particular, along the portion 58 shown in FIG. 3. Thisportion of the ferrule lies adjacent a relatively short end portion ofthe hose having no helical wire extending about its circumference. Thisshort end portion of the hose is sealingly clamped between the ferrule14 and the end fitting. Preferably, a third swaging step is carried outon the upper portion of the ferrule using a third split ring die similarto, but slightly smaller than, the second split ring die in order toensure a good, uniform seal. However, a third swaging step may not berequired under some circumstances.

[0050] It is desirable that the outer diameter of the nipple section 28in the present coupling be very close to the inner diameter of the hoseend. In a particularly preferred embodiment of the invention, theclearance between the inside of the hose end and the nipple in itscylindrical section 40 is only 20/1000ths inch. By having this verysmall clearance, it has been found that three swaging steps aresufficient to finish the hose coupling and provide a good, lasting seal.

[0051] In addition to its initial ease of manufacture, a couplingconstructed in accordance with the invention can often be repairedeasier than some prior art couplings. For example, if a coupling madewith the end fitting 12 and ferrule 14 should start to leak after aperiod of time, it is often possible to repair the coupling by simplypushing it through the aforementioned manufacturing dies again. If oneattempts to repair prior art couplings that use a special seal or sealsor a sealing material, it may be necessary to go through a timeconsuming process of removing contaminants and unwanted material fromthe coupling prior to making the actual repair.

[0052] The above described wire lock including the depression 46 isparticularly useful for large diameter or large bore hose such as dockhose having a diameter of 6 to 8 inches. It will be appreciated that thefailure of a coupling in a large hose of this type can be disastrous,possibly resulting in injury and/or a contaminating spill. The use ofthe aforementioned wire lock provides an extremely secure couplingsystem that can be readily inspected by users of the hose. By looking atthe wire lock one can determine whether or not the hose has been overpressured, in which case the end section of the outer wire 22 may not beseen in the depression or it may be partially withdrawn from thedepression.

[0053] It will be apparent to one skilled in this art that variousmodifications and changes are possible to the hose coupling of theinvention described herein including the method of manufacturing same.Accordingly, all such modifications and changes as fall within the scopeof the accompanying claims are intended to be part of this invention.

I therefore claim:
 1. A reinforced hose coupling comprising: an endfitting having first and second, axially extending sections, said firstsection comprising a connecting element and said second sectionproviding a nipple element having external grooves formed thereon; ametal ferrule mounted on and about said nipple element and connected tosaid end fitting, said ferrule having a generally cylindrical wall andan external depression formed in a side of said wall and projectingradially inwardly towards said nipple element, two spaced-apart holesbeing formed in said depression and through said wall; and a reinforcedhose end having flexible tubular layers crimped between said ferrule andsaid nipple element, said hose end having a helical wire extending aboutthe exterior of said flexible tubular layers, an end piece of said wireextending through said two holes and across said depression.
 2. A hosecoupling according to claim 1 wherein said depression is elongate in thecircumferential direction of said ferrule and said two holes are formedat opposite ends of said depression.
 3. A hose coupling according toclaim 1 wherein said hose end also has an inner helical wire extendingabout the interior of said flexible tubular layers and an end portion ofsaid inner helical wire extends along and engages said external groovesof said nipple element.
 4. A hose coupling according to claim 2 whereinsaid tubular layers include one or more plastic tubular layers whichextend axially beyond said helical wire that extends about the exteriorof the tubular layers, the end portion of the plastic tubular layerslocated beyond said helical wire being pressed tightly between saidferrule and the nipple element and thereby forming a seal able towithstand high fluid pressure.
 5. A hose coupling according to claim 1wherein said ferrule is formed with a circumferentially extendinginternal rim at one end thereof and said rim extends into acircumferential groove formed in said end fitting in order tomechanically secure said ferrule to said end fitting.
 6. A hose couplingaccording to claim 5 wherein said ferrule has a first axially extendingportion with a first external diameter and a second, axially-extendingportion with a second external diameter which is less than said firstexternal diameter, and wherein the first portion of the ferrule extendsabout said helical wire.
 7. A hose coupling according to claim 6 whereinsaid external grooves on the nipple element form a two start thread andsaid hose end has an inner helical wire extending about the interiorthereof, an end portion of said inner helical wire extending along oneof two spiral grooves formed by said thread.
 8. A hose couplingaccording to claim 6 wherein said flexible tubular layers include layersof polypropylene fabric and film and said layers extend beyond an end ofsaid helical wire that extends about the exterior of the tubular layers.9. A method of making a coupling for reinforced, flexible hosecomprising: providing a flexible hose reinforced by means of helicalwire extending about the interior of said hose and having one end onwhich a coupling is to be provided, said hose including flexible tubularlayers which axially extend beyond an end of said helical wire at saidone end of the hose; placing a metal ferrule over said hose and adjacentto said one end of said hose, said ferrule being formed with acircumferentially extending internal rim at an end of said ferruleclosest to said one end of the hose; inserting an end fitting into saidone end of said hose, said fitting having first and second, axiallyextending sections, said first section comprising a connecting elementthat projects from said one end of the hose and said second sectionproviding a nipple element with external grooves formed thereon, saidnipple element being placed in said hose so that said helical wireextends along said external grooves, said end fitting having an externalcircumferential groove formed therein and spaced from the ends thereof,swaging said metal ferrule with a first die and thereby driving saidinternal rim into said circumferential groove and mechanicallyconnecting said ferrule to said end fitting and clamping a portion ofsaid helical wire in said external grooves of said nipple element whichsecures said hose to said end fitting; and swaging said metal ferrulewith at least one follower die of smaller inner diameter than said firstdie and thereby clamping the tubular layers which extend beyond the endof said helical wire tightly between said ferrule and said end fittingin a sealing manner.
 10. A method of making a coupling according toclaim 9 wherein said end fitting is inserted into said one end of thehose by screwing the end fitting relative to said one end of the hose inorder to thread said helical wire into said external grooves of thenipple element.
 11. A method of making a coupling according to claim 9wherein said metal ferrule is swaged with an initial follower die havinga predetermined inner diameter smaller than the inner diameter of saidfirst die and is subsequently swaged with a second follower die havingan inner diameter smaller than said predetermined inner diameter.
 12. Amethod of making a coupling according to claim 11 wherein said flexiblehose is further reinforced by an outer helical wire which extends aroundthe exterior of said flexible tubular layers, said tubular layers extendaxially beyond an end of said outer helical wire, and the swaging stepwith the first die clamps portions of both helical wires between saidferrule and said end fitting.
 13. A method of making a couplingaccording to claim 12 wherein said metal ferrule has an externaldepression formed in a side thereof, two, spaced-apart holes beingformed in said depression, and an end piece of said outer helical wireis inserted through one of said two holes, is passed through saiddepression, and is then manipulated so as to pass out through the otherof the two holes before said ferrule is swaged with the first die.
 14. Areinforced hose coupling comprising: an end fitting having first andsecond axially-extending tubular sections, said first and secondsections being separated by a circumferential groove formed in anexterior surface of said end fitting, said first tubular sectioncomprising a connecting element and said second section having anexternal helical groove that spirals about its circumference; a flexiblehose end comprising flexible tubular layers of plastics or rubbermaterial and an inner helical wire extending about the interior of saidtubular layers, said second section of the end fitting extending intosaid hose so that said helical wire extends along and in said helicalgroove and circumferentially about said second section, an axialextension of said tubular layers extending beyond an adjacent end of thehelical wire and along the exterior of said second section; and a metalferrule mounted on said hose end and extending around an end section ofsaid helical wire and said axial extension of said tubular layers, saidferrule having an internal rim at one end which extends into saidcircumferential groove in order to mechanically connect said ferrule tosaid end fitting, wherein said axial extension of said tubular layers isclamped between said ferrule and said end fitting, thereby forming afluid tight seal.
 15. A hose coupling according to claim 14 wherein saidflexible hose end also has an outer helical wire extending about theexterior of said flexible tubular layers and ending near said adjacentend of the inner helical wire.
 16. A hose coupling according to claim 14wherein said ferrule has a first, axially-extending portion with a firstexternal diameter and a second, axially-extending portion with a secondexternal diameter which is less than said first external diameter, andwherein the first portion of the ferrule extends around said innerhelical wire and the second portion extends around said axial extensionof said tubular layers.
 17. A coupling device for flexible, reinforcedhose having a helical support wire extending about the exterior offlexible tubular layers, said device comprising: an end-fittingincluding means for connecting the device to another fitting and anipple element for insertion into an end of said hose; and a metalferrule for mounting on said end-fitting so that said ferrule extendsaround said nipple element and an end section of said hose, said ferrulehaving an external depression formed in a side thereof and twospaced-apart holes formed in said depression and positioned to receivean end of said helical support wire so that the latter can extendthrough said holes and across said depression.
 18. A coupling deviceaccording to claim 17 wherein said depression is elongate in thecircumferential direction of said ferrule and said two holes are formedin opposite ends of said depression.
 19. A coupling device according toclaim 18 wherein said ferrule has an internal rim at one end which issized and adapted to extend into a circumferential groove formed in anexterior surface of said end-fitting in order to connect the ferrule tothe end-fitting.
 20. Apparatus for making a coupling for flexible hosereinforced by means of a helical wire extending about the interior ofsaid hose, said apparatus comprising: a supporting device for holdingone end of said hose and a generally cylindrical metal ferrule arrangedover an end section of said hose during operation of the apparatus, saidferrule being formed with a circumferentially extending internal rimlocated at an end of said ferrule closest to said one end of the hoseand having an initial first external diameter; a first annular dieforming a circular die opening having a minimum diameter a littlesmaller than said first external diameter; a second annular die forminganother circular die opening having a minimum diameter a little smallerthan said minimum diameter of the first die; a mounting arrangement forrigidly connecting each of said first and second dies to a hydraulic ramso that each die can be driven linearly along the exterior of saidferrule starting at the end of the ferrule having said internal rim, theswaging action of said first die causing said end section of the hose,including an end portion of said helical wire to be clamped firmlybetween said ferrule and an end-fitting positioned within said endsection of the hose, and causing said internal rim to be deformedradially inwardly into an annular groove formed around said end-fittingwhile a subsequent swaging action with the second die causes arelatively short end portion of the hose having no helical wireextending about its circumference to be sealingly clamped between saidferrule and said end-fitting, said further swaging action occurring onlyalong a section of said ferrule immediately adjacent said short endportion of the hose.
 21. Apparatus for making a hose coupling accordingto claim 20 including a third annular die forming another circular dieopening having a minimum diameter a little smaller than said minimumdiameter of the second annular die, said third die being usable for afurther swaging action after use of said second die.
 22. Apparatus formaking a coupling according to claim 20 wherein each of the annular diesincludes a split die ring made up of two semi-circular die sections andsaid mounting arrangement includes an annular mounting ring in whichsaid die ring is detachably mounted.
 23. Apparatus for making a couplingaccording to claim 22 wherein said mounting arrangement further includesa rotatable cam ring extending about said mounting ring and mountedthereon and a number of retaining pins having heads at their outer ends,said heads being arranged in said cam ring, wherein said pins can bemoved by rotation of said cam ring from a first position where innerends of said pins engage and hold said split die ring in said mountingring to a second position where said pins are disengaged from said splitdie ring.
 24. Apparatus for making a coupling according to claim 22wherein said mounting arrangement includes a tubular extension mountableat one end thereof to said hydraulic ram and connectible at an oppositeend thereof to said mounting ring, said tubular extension forming achamber sized to accommodate said end-fitting and said ferrule duringsaid swaging actions.
 25. Apparatus for making a coupling according toclaim 22 wherein each annular die has an annular outer surface engagingan annular inner surface of said mounting ring and both said outersurface and said inner surface extend at an acute angle ranging between10 and 20 degrees to a central axis of the respective annular die asseen in cross-section through said central axis.
 26. Apparatus formaking a coupling according to claim 22 wherein each annular die has anannular outer surface engaging an annular inner surface of said mountingring and both said outer surface and said inner surface extend at anacute angle of about 15 degrees to a central axis of the respectiveannular die as seen in cross-section through said central axis.
 27. Dieapparatus for swaging a tubular metal body, comprising: a split die ringforming a circular opening and made up of two semi-annular die sectionseach having a radially inner surface for engaging and shaping said metalbody and a radially outer surface which in radial cross-section extendsat an acute angle to a central axis of said circular opening; an annulardie body surrounding and supporting said die ring, said die body havingan annular, sloping engagement surface in contact with said radiallyouter surface of the die ring and parallel thereto and said die bodyhaving a number of pin passageways that extend radially through the diebody; a number of holding pins each extending through a respective oneof said pin passageways and having a head on a radially outer endthereof; and a rotatable cam ring extending about said die body andhaving a number of slots formed therein and spaced about thecircumference of the cam ring, each of said slots extending in agenerally circumferential direction and having a respective one of thepins heads captured therein, wherein said pins can be moved radiallyoutwardly by rotation of said cam ring from a first position where innerends of said pins engage and hold said split die ring in said die bodyto a second position where said pins are disengaged from said split diering.
 28. Die apparatus according to claim 27 wherein both said outersurface of said die ring and said engagement surface of the die bodyextend an acute angle ranging between 10 and 20 degrees to said centralaxis.
 29. Die apparatus according to claim 28 wherein said acute angleis about 15 degrees.